How it works
- Add files: drop CSV, TSV, Excel, JSON, NDJSON or Parquet files, or paste data. Each file becomes a table named after it (
sales_2026.csvbecomessales_2026); each sheet of an Excel workbook becomes its own table. - Column names and types are detected automatically. Click a table or column name in the sidebar to insert it into your query.
- Write SQL and press
Ctrl+Enter. Select part of the text to run only that part. - Sort and filter the result, then export it as CSV, JSON or Excel.
New to it? Click Load sample for an orders and a managers table, then try the example buttons.
Useful queries
-- Totals per group
SELECT region, count(*) AS orders, sum(quantity * unit_price) AS revenue
FROM orders GROUP BY region ORDER BY revenue DESC;
-- Find duplicates
SELECT email, count(*) FROM customers GROUP BY email HAVING count(*) > 1;
-- Join two files (like VLOOKUP, but for every row at once)
SELECT o.*, c.country FROM orders o LEFT JOIN customers c ON c.id = o.customer_id;
-- Quick statistics for every column
SUMMARIZE orders;The engine is DuckDB, which speaks standard SQL plus handy extras: GROUP BY ALL, EXCLUDE and REPLACE in SELECT *, window functions, QUALIFY, PIVOT, regular expressions, date functions such as date_trunc, and CREATE TABLE … AS to save intermediate results.
Big files, kept private
Files are read directly from your disk by the database running in your browser; nothing is uploaded, so confidential exports are safe. DuckDB is a columnar engine built for analytics, so grouping and joining millions of rows usually takes seconds. The engine itself (about 7 MB) is downloaded the first time you add a file and kept by your browser afterwards. Results show up to 200,000 rows; export to get them all, or add LIMIT and aggregates to keep results small.
Frequently asked questions
Can I run SQL on a CSV file without a database?
Yes. Add the file here and it becomes a table you can query straight away. The database (DuckDB) runs inside your browser, so there is nothing to install and no server involved.
Can I join two CSV or Excel files?
Yes. Add both files; each becomes a table. Then use JOIN, for example SELECT * FROM orders o JOIN customers c ON c.id = o.customer_id. It works like VLOOKUP across every row at once.
How large can the files be?
Files are read from disk rather than loaded whole, so files of several hundred megabytes work in most browsers. The limit depends on your computer's memory, especially for joins and sorting.
Which SQL dialect is used?
DuckDB SQL, which follows PostgreSQL closely and adds analytics features such as GROUP BY ALL, QUALIFY, PIVOT and SUMMARIZE.
Is my data uploaded anywhere?
No. Your files are read by your browser. Only the DuckDB program itself is downloaded from a public CDN the first time you use the tool.